Reclamation of waste tyre rubber with nitrous oxide

The reaction of tyre rubber crumb with nitrous oxide (N2O) in an organic solvent at 180–230 °C and pressure of 3–5 MPa was studied. The process is accompanied by controllable destruction of vulcanised rubber with the formation of a plastic reclaim product consisting of a sol and gel fractions. The amount of the sol fraction increases proportionally to the conversion of the rubber CC bonds in the reaction with N2O and can be regarded as a measure of the degree of vulcanisate destruction. The method is applicable to the recycling of both rubber crumb and tyre chips.